Because Bush lacks the balls to actually veto a bill, particularly a spending bill, he's now claiming he needs the line item veto to "control spending" (spending for which he is greatly responsible), among other reasons. (Earth to G.W.--maybe if you and Congress stopped spending like a bunch of drunken sailors, you wouldn't need the line item veto you now so hypocritically desire.)
Personally, I like the concept of a line item veto and am a staunch supporter of its present use in many states (almost all states have this gubernatorial power). However, with respect to a federal line item veto, as much as I'd love a president to have it--Clinton did for all of two years before the Supreme Court struck it down in this decision of 1998--I believe it is unconstitutional. It was clearly unconstitutional then, as explained in the 1998 decision, and I believe it is unconstitutional now, in its current talked about format of some enhanced "recission" authority.
Interestingly, though, I find Justice Scalia's arguments about standing in the 1998 case significant, for I believe that those who brought this suit lacked standing. I believe that a Member of Congress should have been the only one permitted to challenge the veto act.
Mr. Will writes an excellent column on this, one with which I agree.
Here is Will's column on this.
Here is an article on the 1998 SCOTUS decision.
Here is some more info on the case, Clinton v. City of New York.
[ March 16, 2006, 09:11 AM: Message edited by: MIB ]